N.Y.C. Charter § 484: Section 484. Designation of officers to act.

The commissioner may designate a clerk or chief of a bureau, who shall have power, when thereunto authorized by the commissioner by instrument in writing to be filed in the offices of the mayor and comptroller, to sign warrants and perform such other duties incidental thereto as may be required during the absence of the commissioner, and for a period of time to be designated in the instrument.